The distinction between Parrot and Perl6 seems really confusing. Is Parrot wasting a lot of effort trying to be a compiler for a host of languages? What benefit would there be to creating such a universal compiler? Would the development of Perl6 itself be faster if Parrot focused only on Perl6?

Parrot is not a compiler. It's a virtual machine. It's an assembly language and environment that compilers can target. Parrot has a few tools for writing compilers though. And I wouldn't say that it is wasted effort.

Perl 6 is a language that has nothing to do with Parrot except that the Rakudo implementation utilizes Parrot as it's back end. There are other Perl 6 implementations that utilize other back ends.

I think that if Parrot only catered to Perl 6, then it would make some things simpler for Rakudo, but many things more complex for other languages. Also, they'd give up one of their main selling points: sharing between languages.

... if Parrot only catered to Perl 6, then it would make some things simpler for Rakudo, but many things more complex for other languages.

Beyond that, if Parrot were to support native versions of both Perl 5 and Perl 6 (and that is indeed a goal of Parrot), it'd still be general enough to support many kinds of dynamic languages besides Perl 5 and 6.